2 * Copyright (c) 2005 Rene Scharfe
8 #define RECORDSIZE (512)
9 #define BLOCKSIZE (RECORDSIZE * 20)
11 #define TYPEFLAG_AUTO '\0'
12 #define TYPEFLAG_REG '0'
13 #define TYPEFLAG_LNK '2'
14 #define TYPEFLAG_DIR '5'
15 #define TYPEFLAG_GLOBAL_HEADER 'g'
16 #define TYPEFLAG_EXT_HEADER 'x'
18 #define EXT_HEADER_PATH 1
19 #define EXT_HEADER_LINKPATH 2
21 static const char tar_tree_usage
[] = "git-tar-tree <key> [basedir]";
23 static char block
[BLOCKSIZE
];
24 static unsigned long offset
;
26 static const char *basedir
;
27 static time_t archive_time
;
30 struct path_prefix
*prev
;
34 /* tries hard to write, either succeeds or dies in the attempt */
35 static void reliable_write(void *buf
, unsigned long size
)
38 long ret
= xwrite(1, buf
, size
);
42 die("git-tar-tree: %s", strerror(errno
));
44 die("git-tar-tree: disk full?");
51 /* writes out the whole block, but only if it is full */
52 static void write_if_needed(void)
54 if (offset
== BLOCKSIZE
) {
55 reliable_write(block
, BLOCKSIZE
);
60 /* acquire the next record from the buffer; user must call write_if_needed() */
61 static char *get_record(void)
63 char *p
= block
+ offset
;
64 memset(p
, 0, RECORDSIZE
);
70 * The end of tar archives is marked by 1024 nul bytes and after that
71 * follows the rest of the block (if any).
73 static void write_trailer(void)
86 * queues up writes, so that all our write(2) calls write exactly one
87 * full block; pads writes to RECORDSIZE
89 static void write_blocked(void *buf
, unsigned long size
)
94 unsigned long chunk
= BLOCKSIZE
- offset
;
97 memcpy(block
+ offset
, buf
, chunk
);
103 while (size
>= BLOCKSIZE
) {
104 reliable_write(buf
, BLOCKSIZE
);
109 memcpy(block
+ offset
, buf
, size
);
113 tail
= offset
% RECORDSIZE
;
115 memset(block
+ offset
, 0, RECORDSIZE
- tail
);
116 offset
+= RECORDSIZE
- tail
;
121 static void append_string(char **p
, const char *s
)
123 unsigned int len
= strlen(s
);
128 static void append_char(char **p
, char c
)
134 static void append_path_prefix(char **buffer
, struct path_prefix
*prefix
)
138 append_path_prefix(buffer
, prefix
->prev
);
139 append_string(buffer
, prefix
->name
);
140 append_char(buffer
, '/');
143 static unsigned int path_prefix_len(struct path_prefix
*prefix
)
147 return path_prefix_len(prefix
->prev
) + strlen(prefix
->name
) + 1;
150 static void append_path(char **p
, int is_dir
, const char *basepath
,
151 struct path_prefix
*prefix
, const char *path
)
154 append_string(p
, basepath
);
157 append_path_prefix(p
, prefix
);
158 append_string(p
, path
);
163 static unsigned int path_len(int is_dir
, const char *basepath
,
164 struct path_prefix
*prefix
, const char *path
)
166 unsigned int len
= 0;
168 len
+= strlen(basepath
) + 1;
169 len
+= path_prefix_len(prefix
) + strlen(path
);
175 static void append_extended_header_prefix(char **p
, unsigned int size
,
178 int len
= sprintf(*p
, "%u %s=", size
, keyword
);
182 static unsigned int extended_header_len(const char *keyword
,
183 unsigned int valuelen
)
186 unsigned int len
= 1 + 1 + strlen(keyword
) + 1 + valuelen
+ 1;
194 static void append_extended_header(char **p
, const char *keyword
,
195 const char *value
, unsigned int len
)
197 unsigned int size
= extended_header_len(keyword
, len
);
198 append_extended_header_prefix(p
, size
, keyword
);
199 memcpy(*p
, value
, len
);
201 append_char(p
, '\n');
204 static void write_header(const unsigned char *, char, const char *, struct path_prefix
*,
205 const char *, unsigned int, void *, unsigned long);
207 /* stores a pax extended header directly in the block buffer */
208 static void write_extended_header(const char *headerfilename
, int is_dir
,
209 unsigned int flags
, const char *basepath
,
210 struct path_prefix
*prefix
,
211 const char *path
, unsigned int namelen
,
212 void *content
, unsigned int contentsize
)
215 unsigned int pathlen
, size
, linkpathlen
= 0;
217 size
= pathlen
= extended_header_len("path", namelen
);
218 if (flags
& EXT_HEADER_LINKPATH
) {
219 linkpathlen
= extended_header_len("linkpath", contentsize
);
222 write_header(NULL
, TYPEFLAG_EXT_HEADER
, NULL
, NULL
, headerfilename
,
223 0100600, NULL
, size
);
225 buffer
= p
= malloc(size
);
227 die("git-tar-tree: %s", strerror(errno
));
228 append_extended_header_prefix(&p
, pathlen
, "path");
229 append_path(&p
, is_dir
, basepath
, prefix
, path
);
230 append_char(&p
, '\n');
231 if (flags
& EXT_HEADER_LINKPATH
)
232 append_extended_header(&p
, "linkpath", content
, contentsize
);
233 write_blocked(buffer
, size
);
237 static void write_global_extended_header(const unsigned char *sha1
)
242 size
= extended_header_len("comment", 40);
243 write_header(NULL
, TYPEFLAG_GLOBAL_HEADER
, NULL
, NULL
,
244 "pax_global_header", 0100600, NULL
, size
);
247 append_extended_header(&p
, "comment", sha1_to_hex(sha1
), 40);
251 /* stores a ustar header directly in the block buffer */
252 static void write_header(const unsigned char *sha1
, char typeflag
, const char *basepath
,
253 struct path_prefix
*prefix
, const char *path
,
254 unsigned int mode
, void *buffer
, unsigned long size
)
256 unsigned int namelen
;
258 unsigned int checksum
= 0;
260 unsigned int ext_header
= 0;
262 if (typeflag
== TYPEFLAG_AUTO
) {
264 typeflag
= TYPEFLAG_DIR
;
265 else if (S_ISLNK(mode
))
266 typeflag
= TYPEFLAG_LNK
;
268 typeflag
= TYPEFLAG_REG
;
271 namelen
= path_len(S_ISDIR(mode
), basepath
, prefix
, path
);
273 ext_header
|= EXT_HEADER_PATH
;
274 if (typeflag
== TYPEFLAG_LNK
&& size
> 100)
275 ext_header
|= EXT_HEADER_LINKPATH
;
277 /* the extended header must be written before the normal one */
279 char headerfilename
[51];
280 sprintf(headerfilename
, "%s.paxheader", sha1_to_hex(sha1
));
281 write_extended_header(headerfilename
, S_ISDIR(mode
),
282 ext_header
, basepath
, prefix
, path
,
283 namelen
, buffer
, size
);
286 header
= get_record();
289 sprintf(header
, "%s.data", sha1_to_hex(sha1
));
292 append_path(&p
, S_ISDIR(mode
), basepath
, prefix
, path
);
295 if (typeflag
== TYPEFLAG_LNK
) {
296 if (ext_header
& EXT_HEADER_LINKPATH
) {
297 sprintf(&header
[157], "see %s.paxheader",
301 strncpy(&header
[157], buffer
, size
);
306 mode
|= 0755; /* GIT doesn't store permissions of dirs */
308 mode
|= 0777; /* ... nor of symlinks */
309 sprintf(&header
[100], "%07o", mode
& 07777);
311 /* XXX: should we provide more meaningful info here? */
312 sprintf(&header
[108], "%07o", 0); /* uid */
313 sprintf(&header
[116], "%07o", 0); /* gid */
314 strncpy(&header
[265], "git", 31); /* uname */
315 strncpy(&header
[297], "git", 31); /* gname */
317 if (S_ISDIR(mode
) || S_ISLNK(mode
))
319 sprintf(&header
[124], "%011lo", size
);
320 sprintf(&header
[136], "%011lo", archive_time
);
322 header
[156] = typeflag
;
324 memcpy(&header
[257], "ustar", 6);
325 memcpy(&header
[263], "00", 2);
327 sprintf(&header
[329], "%07o", 0); /* devmajor */
328 sprintf(&header
[337], "%07o", 0); /* devminor */
330 memset(&header
[148], ' ', 8);
331 for (i
= 0; i
< RECORDSIZE
; i
++)
332 checksum
+= header
[i
];
333 sprintf(&header
[148], "%07o", checksum
& 0x1fffff);
338 static void traverse_tree(struct tree
*tree
,
339 struct path_prefix
*prefix
)
341 struct path_prefix this_prefix
;
342 struct tree_entry_list
*item
;
343 this_prefix
.prev
= prefix
;
346 item
= tree
->entries
;
351 unsigned long eltsize
;
353 eltbuf
= read_sha1_file(item
->item
.any
->sha1
,
356 die("cannot read %s",
357 sha1_to_hex(item
->item
.any
->sha1
));
358 write_header(item
->item
.any
->sha1
, TYPEFLAG_AUTO
, basedir
,
360 item
->mode
, eltbuf
, eltsize
);
361 if (item
->directory
) {
362 this_prefix
.name
= item
->name
;
363 traverse_tree(item
->item
.tree
, &this_prefix
);
364 } else if (!item
->symlink
) {
365 write_blocked(eltbuf
, eltsize
);
372 /* get commit time from committer line of commit object */
373 static time_t commit_time(void * buffer
, unsigned long size
)
379 char *endp
= memchr(p
, '\n', size
);
380 if (!endp
|| endp
== p
)
383 if (endp
- p
> 10 && !memcmp(p
, "committer ", 10)) {
384 char *nump
= strrchr(p
, '>');
388 result
= strtoul(nump
, &endp
, 10);
393 size
-= endp
- p
- 1;
399 int main(int argc
, char **argv
)
401 unsigned char sha1
[20];
402 unsigned char commit_sha1
[20];
407 setup_git_directory();
414 if (get_sha1(argv
[1], sha1
) < 0)
415 usage(tar_tree_usage
);
418 usage(tar_tree_usage
);
421 buffer
= read_object_with_reference(sha1
, "commit", &size
, commit_sha1
);
423 write_global_extended_header(commit_sha1
);
424 archive_time
= commit_time(buffer
, size
);
427 tree
= parse_tree_indirect(sha1
);
429 die("not a reference to a tag, commit or tree object: %s",
432 archive_time
= time(NULL
);
434 write_header((unsigned char *)"0", TYPEFLAG_DIR
, NULL
, NULL
,
435 basedir
, 040777, NULL
, 0);
436 traverse_tree(tree
, NULL
);